Silver Alert, a Moore 24 is being outfitted for longer distances.

Charting is covered by paper charts (full info with no zooming - yeah), Garmin Gpsmaps 742xs with all the N2000 network connectivity, and a handheld Garmin. Sailing will be in US as well as Canada.

There othe additional digital devices that can be used as another backup, or as a standalone device on paddle craft. Here is what is available to use-

Toshiba laptop running Windows Vista
Acer Chrome
Fire 7 or Fire HD10

I have been uninvolved with any electronic navigation for the last 20 years. My question for the best alternative, if there is one, what are the general approaches to have an independent digital chart backup.

As an aside, even though the N2K systems are supposed to all be compatible, with all parts from one source (Garmin) there is only one call for system troubleshooting.

Thanks.

Ants